Angels & Demons - The Real Physics

Lecture Night

21 May 2009

The real physics behind the new Dan Brown film, Angels and Demons,
was discussed by Dr Robert Flack, of UCL's Institute of Origins,
at an evening lecture. In this sequel to The Da Vinci Code, an antimatter bomb, stolen from
the European particle physics laboratory CERN, is used to terrorize
the Vatican. Is such a bomb possible in the real world? How would
such a bomb compare with conventional and nuclear devices? The book
suggests that antimatter has potential as a future planet-wide energy
resource. These questions amongst others were considered in the
lecture.

Antimatter was first proposed by an English physicist Paul Dirac in
1928 and opened a Pandora's box of speculation and conjecture. Now
the picture we have of antimatter is totally different. For example
our own bodies contain a small amount of Potassium-40, which emits
4000 antiparticles - positrons - every second, but we still live to
tell the tale!

Cosmic rays, which contain antimatter, also bombard the Earth and us,
thousands of time a second and using simple instruments, such as cloud
and spark chambers, it is possible to "see" antimatter. The first
observation of a positron was made by American physicist Carl
Anderson, using a cloud chamber, an achievement for which he received
the Nobel Prize in 1936. Following in his footsteps we had both
a cloud and spark detector on display and working at the lecture.

The book also suggests that by making anti-matter we are re-creating
the beginning of the Universe and also refers to it as the "God
Particle". Both these statements are somewhat confusing and
misleading. At the beginning of the Universe it is believed the Big
Bang produced equal amounts of matter and antimatter but now matter
dominates and antimatter only exists in microscopic quantities. We
have learned how to produce anti-matter in larger quantities for use
in medicine and fundamental research, but the term "God Particle"
was coined for the Higgs Boson particle and did not have any religious
connotations. The particle was first postulated by former UCL
lecturer Peter Higgs, who referred to it as being the origin of
mass. However, the Higgs Boson has never been observed and it is
experiments at CERN, such as the Large Hadron Collider, that will
search for it.

The lecture was not just about the film and more general questions
relating to anti-matter were also considered. For example, can we ever
visit the stars? Near-light speed would need to be achieved to get to
the closest star in a reasonable time - i.e. the
lifetime of an astronaut - and anti-matter driven
engines have been proposed as one solution. How close are we to
making this a reality? Unfortunately, it would take well over a
million years and several times the world's GDP to produce enough
antimatter to destroy the Vatican, let alone travel to the stars!

UCL has a world class particle physics group and plays a significant
role in making the UK a world leader in the subject. The UCL group
are significant members of many major international collaborations and
their work was also presented.

The whole lecture has been filmed and is accessible via flash video player below: